The weather impacts every aspect of life whether it be human, animal, or plant-life. Long-term weather, or climate, forces humans and all other life forms to continuously adapt in order to survive most efficiently within the climate type of a given region. On a geological time scale of thousands or millions of years, the earth has experienced much warmer and much cooler climates than those today. Humans, however, are influenced by climate changes occurring over much shorter time scales. Most are familiar with the term, El Niņo, which is the name given to the two to five year change in climate associated with abnormally warm equatorial Pacific Ocean sea-surface temperatures. During an El Niņo period, news stories abound about how this phenomena has caused global havoc such as floods, droughts, severe hot and cold, etc.

During the years 600-1850, Europe experienced climate changes that were far-reaching - every aspect of life in Europe was influenced including, among others, exploration, agriculture, health, deaths, economics, and art and literature. In particular, the rise and fall of the Viking civilization in Greenland and Iceland is directly linked to climate changes.

Note to general public:

My position on the current global warming is the same as the overwhelming majority of international climate scientists: the current rate of global warming is unprecedented and is being caused by humans. In no way can my summary of the research regarding the impact of regional climate change on the Viking civilization and Europe during the Little Ice Age be used to "prove" the current global warming is due to a natural cycle.

I highly recommend that you read the information being presented by the Intergovernmental Panel on Climate Change (IPCC) at http://www.ipcc.ch/. Please view Global Warming: Man or Myth which addresses many of the questions asked about the human impact on the current climate change in a very simple format. The climate change being observed today is unprecedented in modern times and can only be explained by the rapid increase of greenhouse gases by human activities. There are no known natural forces that could have caused the modern climate change.